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Nutrition is a science
Fruit and more;
be healthy by following
the advice of
the experts
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Eat more cereal, pulses, fruit and vegetables
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These kinds of food are vital because they contain carbohydrates (especially starch and fibre). They also contain vitamins, minerals and other substances that are very important for our health. What is more, cereal, and pulses in particular, are also good sources of protein. Many studies have shown that a diet that is rich in cereal, pulses and fruit and vegetables protects us from many illnesses that are very common in developed countries, in particular various kinds of tumours and cardiovascular diseases (coronary artery diseases, hypertension, heart attacks) cataract, illnesses of the respiratory apparatus (asthma and bronchitis) and illnesses of the digestive system (diverticulitis, constipation) etc. Consuming sufficient quantities of fruit and vegetables, furthermore, ensures that we receive a significant intake of nutrients (vitamins, minerals, organic acids), yet at the same time, it allows us to reduce the energy density of our diet. Firstly because the quantity of fat and the overall calories we eat are limited, and secondly because these kinds of food make us feel particularly full.
Why should we eat more cereal, pulses and fruit and vegetables? |
Because they are rich in starch.
Cereal and cereal products have always been the main source of carbohydrates in the Italian diet. In a balanced diet, about 60% of our calorie intake should derive from carbohydrates, of which, at least three quarters, should be in the form of complex carbohydrates, and no more than the remaining quarter should be in the form of simple carbohydrates. Carbohydrates are important because our body absorbs and uses them easily, without producing metabolic waste, thus ensuring that our cells are supplied with glucose i.e. energy. Our digestive system has to work harder to transform starch into glucose, so it is absorbed more slowly. While simple carbohydrates are digested and absorbed more easily. Consequently, the presence of both kinds of carbohydrates – simple and complex - at the same time, in the proportions mentioned above, ensures that our body gets a constant and prolonged supply of energy, which avoids sudden variations in the level of glucose in our blood (glycaemia). |
Because they are rich in fibre.
Cereals and cereal products, pulses and fruit and vegetables, are also a good source of dietary fibre. Dietary fibre has no nutritional or energy value in itself (except for a small quantity of energy which is produced by the fatty acids that form during the fermentation process that takes place in the colon), however, it is very important for the regulation of various bodily functions. Fibre is mostly made up of complex carbohydrates that are not directly usable by the human body. Some of the constituents (cellulose, hemicellulose and lignin) are not water soluble, and act primarily on the gastrointestinal system, slowing down the stomach’s emptying process, and facilitating the transit of food in the intestines and the expulsion of faeces. While other constituents (pectin, gum and mucilage) are water soluble – they form resistant gels in water – and regulate the absorption of certain nutrients (for instance sugars and fats) reducing it and slowing it down , thus helping to control levels of glucose and cholesterol in the blood (such as in varices), and important chronic-degenerative illnesses, such as tumours of the colon-rectum in particular (probably due to the dilution of carcinogenic substances, and to the reduction of the time they spend in contact with the mucus of the intestine, and for other reasons that are sill unknown), as well as diabetes and cardiovascular diseases (probably by regulating blood glucose and cholesterol levels). The recommended daily dose of fibre is around 30 grams a day, which is more than the average quantity that is consumed in Italy today. To meet these recommended levels, you should consume fibre-rich food more often, rather than resorting to dietary products with a high concentration of fibre. |
Because they contain important vitamins and minerals.
Fruit and vegetables are an excellent source of vitamins: for example oranges, tomatoes and kiwis contain vitamin C and folates, carrots, apricots, and green-leafed vegetables contain pro-vitamin A, and pulses and cereals contain thiamine, niacin and folates. Fruit and vegetables are also a rich source of minerals (green-leafed vegetables contain calcium and iron, potatoes and tomatoes contain potassium). Though animal products contain greater quantities of the latter, compared to fruit and vegetables.
Because they contain substances that have a protective action.
The beneficial effects of eating fruit, vegetables and pulses are also due to the fact that some of their constituents have a prevalently antioxidant protective action, which they carry out by combating free radical action. This process is very important since free radical action can alter the structure of cell membranes and of genetic material (DNA), making our bodies susceptible to early aging processes and to a whole gamut of reactions that can cause various forms of tumour. This protective action is carried out by the constituents we have already mentioned (vitamins and minerals), but it is also carried out by other constituents which, despite their smaller quantities, are equally as active from a biological point of view, and they work through various mechanisms, the main one being precisely the antioxidant one. |
The most common antioxidant classes contained in fresh fruit and vegetables are:
- ascorbic acid (vitamin C);
- carotenoids (the yellow, orange and red pigmentation that yellowy-orange fruit and vegetables are rich in – due to the presence of ß-carotene – and the red pigmentation of tomatoes – due to the presence of licopene);
- phenolic constituents (high concentrations of which are present in almost all vegetables, as well as in grapes, and therefore wine, too);
- tocopherols (contained in oily seeds and green-leafed vegetables).
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| What is more, eating fruit and vegetables ensures a significant intake of certain minerals (such as selenium and zinc) that act with our body’s antioxidant defence system. Other fruit and vegetable substances have been studied to explore their potential cancer prevention effects. For example, various sulphide constituents facilitate the elimination of carcinogenic substances at a cellular level: isocyanates and dithioles, which vegetables belonging to the cruciferous family are rich in - such as broccoli, cauliflower, and cabbage - and allicin (sulphur-nutrients) that garlic is rich in etc. The cruciferous family is also rich in indoles, which appear quite effective in contrasting the development of tumours, while soya is among the few nutritional substances that contain isoflavones, phytoestrogens that seem to inhibit the growth of certain tumourous cells. We should also mention folates, vitamins that leafy vegetables, some citrus fruit and other vegetables are rich in. Folates, together with the other B group vitamins, can help to reduce homocysteine levels in the blood, a well-known risk factor with regards to cardiovascular diseases. Women in their fertile years should consume adequate quantities of these substances, as they also protect the foetus from the insurgence of neural tube defects (spina bifida). Finally, the intake of high levels of potassium, which fruit and vegetables are rich in, has been associated with a reduced heart attack death rate. It is important to highlight that until now, no studies have demonstrated that the intake of individual constituents in the form of dietary supplements has the same beneficial effects associated with eating fresh fruit and vegetables. Consequently, it is thought that these beneficial effects must be due primarily to the synergic action of multiple food constituents, many of which are probably yet to be discovered. However, this action seems not to occur when these beneficial
constituents are ingested individually, even if in relatively concentrated forms (dietary supplements etc). |
Advice:
- Consume more portions of fresh fruit and vegetables every day and increase your consumption of fresh and dried pulses, always being careful to limit the quantity of added fat and oil, which can also be substituted with herbs and spices.
- Eat bread, pasta, rice and other cereals regularly (best if whole grain), but avoid adding very fatty sauces and condiments.
- Whenever you can, chooses products made with whole grain flour, not flour to which bran and other fibre has simply been added (read labels).
- To put this advice into practice, follow the portions indicated in the Guidelines at point n.8 “Vary your diet often”.
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(taken from “GUIDLINES FOR HEALTHY ITALIAN NUTRITION” – Ministry of Agricultural and Forestry Policies and INRAN Italian National Institute of Food and Nutrition Research – 2003)
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